Device for arresting light-rays.



F. IVI. BLAiR & F. M. BLACK.

nvms FOR ARRESNNG LIGHT Ws.

n APPUCATON FILED FEB. 2?, 1917. I t l n m.. Pnmn'edhme 2b, MU.

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F. IVI. BLAIR z F. IVI. BLACK.

DEVICE FOR ARRESTING LIGHT RAYS.

APPLICATION FILED FEB. 2. 1911.

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NETE@ STATE@ PATENT FRQIK IJI. BLAIR AND FREDERIC M. BLACK, 0F NEWARK, OHI.

DEVECE FOB. ARRESTING LGHT-RAYS. f

Application led February 27, 1917.

To all lwlw/1L t may concern:

Be it known that we, .FRANK M. BLAIR and Fiumicino M. BLM'K, citizens of the United States. residing at Newark, in the county of Licking and State oi" Uhio, have invented certain new and useful Improvements in Devices for Arresting Light-Rays; and we do hereby declare the following to be a full, clear, and exact description ot' the same when taken in connection with the accompanying drawings, forming part of this specification.

This invention relates to an improved device 'or arresting vlight rays, which is more especially adapted to be used in conjunction with headlights et the scarchlight type, such as are commonly employed on automobiles, features of the invention, however, heilig capable of useful application in otherv types of lamps as well.

device constructed in accordance with the present invention is particularly adapted for the purpose oi' arresting the objectionable tin-rellected or direct rays from the source of light of a headlight, which diverge Widely in front of the headlight, resulting in a curtain of' light, so to speak, which is blinding to a person approaching the light and actually interferes with a View of the lighted sui-laces in front of the headlight by a person stationed in a position behind the. headlight. The rui-tain of light caused by the widelydivergent direct rays is particularly objectionable in thick weather, because the ra'ys illuminate a mist, snowparticles in the air, or a fog, and practically obscure the view in front of the headlight. The present device for arresting these direct rays eliminates the above stated dificulties, and, in so doin-g, oti'ers practically no obstruction whatever to the parallel reflected rays ol the, headlight, so that thel etliciency oi' the latter is not impaired.

For a full uutlerstanding oit the inrcir tion reife-rence is now made to the accompanying drawings, which illustrate a strnctural embodiment of the invention utilizedin conjunction with a headlight of the type such as is commonly employed in autoincbiles and including` a pa rabolic reflector for directingr a straight beam of light in front of the headlight.

ln the drawings:

Figure l is a section'taken through the vertical center of a headlight employing a Specification of Letters Patent. Patented Juin@ 25, .lllll'iiu Serial No. 151,328.

parabolic reflector and provided With the present improvements.

Fig. 2 is a trout elevation of the same.

*'Fig. 3 is a View similar to Fig. l illustrating another modification.

Figs. 4- and 5 are views similar to vFigs. E. and 2 but illustrating another inodilication.

Like characters of reference in the serL eral figures indicate the same parts.

` For convenience all the l'orrns of the^` invention are illustrated in connection with a headlight of a type commonly employed by automobiles and which embodies in its construction a parabolic reflector l. on the iront of which is mounted the usual front .glass 2. A source of light is positioned to lie in the focal center oi and in the longitudinal axis of the parabolic reflector, said axis being indicated by a dotted line AeB. The focal center of the reiiector is Adesignated by the reference character C. Any suitable source of light may be employed, of course, but in accordance with the presentpreferred practice, the source of light is an electric lamp 8 mounted on a' lamp socket fl secured to the reflector l, and lying parallel with the axis A-B of the latter. in a headlight or" this type, rays from the source of light are re 'lccted by the parabolic reflector l through the front glass 2 in line substantially parallel with the axis A-B, as indicated by 'the dot-anddash lines a-b, which substantially parallel rays cause a straight beam of light to be projected in front ot the reflector."

Besides .the parallel reliected rays o-), widely-diverging unretlected or direct' rays (1 -D, indicated by iiull lines `pass from the source of light and would ordinarilyT spread out in front of the lamp to canse a luminous curtain, which, as hereinbefore stated is very objectionable, in that it is primarily the cause of the blinding light projected on a person closely approaching the lamp, and in heavy weather the cause of a very serious obstruction to the View toward the front of a person stationed behind the lamp. Pri- 'marily, the invention is directed to the proof light may besuppressed by this invention, or, in the case of an automobile, only the divergent rays )rojected upwardly from the headlight may lie suppressed permitting the downwardly projecting divergiug direct rays to illuminate the surface of the road directly in front of the automobile.

Referring now to Figs. 1 and 2 which` illustrate an embodiment of the invention for sup ressing or intercepting all of the widelyiverging direct rays- As shown, a tube 6, is mounted on the front glass 2, the sides of the tube being positioned to intel-ce t the Widely divergmg direct rays C-D throughout the entire 360 degrees of the vertical lane of the headlight. The tube 6 may be ma e of any suitable ma` terial adapted to intercept the direct rays C--D and prevent projection of these rays through the front glass 2. The tube 6 is illustrated as round in cross section, but the sha e may obviously be varied, if desired. Said tube extends inwardly from the front glass 2 toward the lamp 3, the lon 'tudinal axis of the tube coinciding prefere ly, with the longitudinal axis A- of the reflector and lamp. It is also preferable that the diameter of the tube be greater than the vertical diameter of the lamp, so that the front portion f the lamp may extend partially within t e tube, asshown, thereby permitting the tube to intercept the most widely divergent direct rays without necessitatin the construction of, a tube of unduly grea diameter. If the diameter of the tube be too lar e, its purpose, of course, would be` defeate for the reason that many of the objectionable divergent direct rays would escape through the interior of the tube. In its preferred embodiment, the tube is made of glass formed integral'with the front glass 2, and the sides of the tube are rendered partially opaque or semi-transparent by frost-v' ing the glass or coloring it so as toy render the sides of the tube practically impervious to the direct rays CFD.

The above described device is very cf#V fectivc for iuterceptiug the Widely divergent rays C-D from the lam 3, and lthus the objectionable curtain in ront o'f the head-'j light is eliminated. As thc sides of the tube/i are parallel with the longitudinal axis --B no interference whatever is offered to the asslage of the parallel reflected rays L -b.

he direct rays A-D passing through the interior of the tube do not diverge so widely asthe rays A--D and hence are not curtain forming. These rays may be permitted to pass through the front glass-without hin drance, or, it desired, theyk' may loe.int'e1'l cepted by frosting or coloring that ort'o'n of the front glass whichvlies within t e side of the tube.

Fig. 3 shows an arrangement for causing the direct rays 2li-DP to be projected parallel with the reflected rays. For this purpose, a lens i' is mounted to cover that p0rtion .of the front glass directlyv iu front of the tube, the leus being indiameter substantially equal to the diameter of the tube,

and of a character to cause the rays A-D- to be projected parallel with reflect-ed rays.

In Figs. 4 and 5, au arrangement is Illustrated Whirh is particularly useful when the headlight is employed for automobile use.

As shown the lower portion S of the side wall ofthe tube is left transparent, while the upper portion 9 is made partially opaque. vWith :this arrangement the upper widely divergent direct rays A--D2 arc in` tercepted and the lower rays A--Da permitted to pass through the front glass so as to light that portion of the road directly in front of an automobile. In automobile use, the lower divergent direct rays are not objectionablmbecause they are beneath the line of vision. j'

What is claimed is 1. A front glass for a projector comprising a transparent 'glass plate adapted to be mounted in front of the' source of light of a proector, said front glass having a frosted lass tube formed integral with the front gass and projecting from the surface of the latter, whereby direct rays `from the source of light are arrested by the tube when the plate 1s mounted in front of a projector.

2. A device for arresting light rays comprising a nrlass plate adarlted to be mounted m fronto a source of 1i t and a glass tube. formed integral with t e glass plate and projecting from the surface of the latter, a portion of thc side wall of the tube-being made partially opaque the other portion of the side wall of the tube being transparent, whereby direct rays from the source of light may be arrested by the partially opaque por,- 'rtion of the tube when the glass plate is anounted in front of the source of light.

In a headlight, the combination of a re- Hector, a. source of light disposed in thi` focal center of the reflector and in the longitudinalaxis of the latter, a glass plate mounted infront of the reflector and source of light provided with a semi-transparent inwardly projecti glass tube, and a lens mounted in froutof t e glass tube.

41' In a' headlight, the combination of a reflector, a source of light disposed in the focal center of the reflector audio the longitudinal axis of the latter, and a glass plato mounted in front of the rcflcctorand source of lightk provided with a light ray arresting inwardly )rejecting glass tube, forinediir tegral wit the plate, the longitudinal axis of the tube coinciding with the longitudinal axis of the reflector. I jf 5. In a headlight, the combination of'a reflector, a source of light disposed in the itsl .focal center of the reflector and in the longitudinal axis of the latter, and a glass plate mounted in front of the reflector and source ol' light provided with a scmi-transparent inwardly projecting glass tube formed intethrough the interior of the tube.

6. ln .1 headlight, the combination of a 1 rellector, a source of light disposed' in the focal center of the reflector and in the lon- 15 `gitudinal axis of the latter, and a glass plate mounted in front of the relector'and source o f light provided with an inwardly projecting glass tube of which the upper portion of the side wall is treated totarrest dlrect light rays and the lower portie/n of the side wall is wholly transparent.

7 1n a headlight, the combination of a reflector, an incandescent lamp bulb,A disposed in the focal center of the reliector and in the longitudinfiil axis of the latter, and a glass plate mounted in front of the reiector and source of light provided with an inwardly projecting-lght arresting glass tube, the d1- auleter of thc tube being greater than the vertical diameter of the lamp bulb and the inner end 'of the tube receiving the forward portion of the lamp bulb.

FRANK M. BLAIR.

FREDERIC M. BLACK. 

